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Analysing how plants in coastal wetlands respond to varying tidal regimes throughout their life cycles
2017
Xie, Tian | Cui, Baoshan | Li, Shanze
Important to conserve plant species in coastal wetlands throughout their life cycle. All life stages in these habitats are exposed to varying tidal cycles. It is necessary to investigate all life stages as to how they respond to varying tidal regimes. We examine three wetlands containing populations of an endangered halophyte species, each subjected to different tidal regimes: (1). wetlands completely closed to tidal cycles; (2). wetlands directly exposed to tidal cycles (3). wetlands exposed to a partially closed tidal regime. Our results showed that the most threatened stage varied between wetlands subjected to these varying tidal regimes. We hypothesis that populations of this species have adapted to these different tidal regimes. Such information is useful in developing management options for coastal wetlands and modifying future barriers restricting tidal flushing.
Mostrar más [+] Menos [-]Underestimation of chemical contamination in marine fish muscle tissue can be reduced by considering variable wet:dry weight ratios
2017
Cresson, Pierre | Travers-Trolet, Morgane | Rouquette, Manuel | Timmerman, Charles-André | Giraldo, Carolina | Lefebvre, Sébastien | Ernande, Bruno
Whether considered as a risk for human health or as ecological tracers, contaminants' concentrations measured in fish muscles are commonly expressed relative to wet or dry mass. Comparison of results required conversion factors (CF) but accurate values are scarce and case-specific. The present paper is aimed at investigating errors linked with the use of the theoretical value. Muscles dry and wet masses were measured in 15 fish species to determine the actual CF. Most CF were lower than the theoretical wet:dry ratio of 5 classically used, with variations at individual and species level. Muscle lipid content (inferred by C/N ratios) was a crucial factor explaining discrepancies, claiming for caution when working with lipid-rich species. The observed variability demonstrated that using the theoretical CF may be inaccurate, when actual CF largely differs from the theoretical value. Dedicated measurement is the better approach when accuracy is required.
Mostrar más [+] Menos [-]Reduction of CO2 emissions with automatic mooring systems. The case of the port of Santander
2017
Ortega Piris, Andrés | Díaz-Ruiz-Navamuel, Emma | Pérez-Labajos, Carlos A. | Oria Chaveli, Jesús
The revolutions in the maritime industry resulting from the implementation of integrated transport systems (bulk) and containerization (regular lines) at first had little effect on traditional mooring systems for ships in port. However, the research into innovation in automated mooring systems with increasingly advanced technologies carried on regardless.The so-called “Automatic Mooring Systems” (AMS), automatic systems that allow vessels to be moored without ropes, are being increasingly implemented in numerous ports in many different countries in the world, particularly in those whose traffic volumes have allowed the threshold of profitability of these infrastructures to be reached. But besides the financial benefits, the implantation of the AMS is having positive effects on the environment by reducing CO2 emissions in many commercial ports.The present work aims to measure for the first time the reduction in the CO2 emissions of merchant vessels as a consequence of the substitution of traditional mooring systems with the new automatic systems, continuing along the lines of previous works in the field of the reduction in CO2 emissions in ports.The estimation is made by applying the EPA and ENTEC “bottom-up” methodologies to the traffic in the port of Santander (Spain) in the year 2014.The implementation of the AMS, when compared to the traditional mooring systems, leads to a reduction in CO2 emissions of 76.78% calculated using the EPA method and 76.63% using the ENTEC method. Hence, the Port Authorities in their long-term planning decisions should promote the introduction of automatic mooring systems wherever the profitability thresholds of traffic allow it, as this will lead to significant environmental benefits by substantially reducing CO2 emissions during the maneuvers of merchant ships in maritime commercial ports.
Mostrar más [+] Menos [-]Hydrogeochemical and isotopic signature of surface and groundwater in a highly industrialized sector of the Rio de la Plata coastal plain (Argentina)
2017
Santucci, L. | Carol, E. | Borzi, G. | García, M.G.
The coastal plain of the middle estuary of the Río de la Plata is a highly industrialized area and is densely populated by sectors. The main human activity in the sector encompassed between the cities of Ensenada and Berisso is associated with the petrochemical industry. In this work, hydrogeochemical and isotopic characteristics of surface and groundwater in the impacted area are analyzed and the results are contrasted with those obtained in an undisturbed protected area. Major and trace elements were determined using standardized methods while the stable isotopes δ18O y δ2H were analyzed by mass spectroscopy. Human impact is evidenced by the occurrence of large variations in the major chemical composition of water, and also by the elevated concentrations of some trace elements that are not contributed from natural sources. These results may contribute to the understanding of chemical processes and pollutants distribution in highly industrialized coastal plain areas.
Mostrar más [+] Menos [-]Evaluation on island ecological vulnerability and its spatial heterogeneity
2017
Ji, Yuan | Shi, Honghua | Wang, Yuanyuan | Guo, Zhen | Wang, Enkang
The evaluation on island ecological vulnerability (IEV) can help reveal the comprehensive characteristics of the island ecosystem and provide reference for controlling human activities on islands. An IEV evaluation model which reflects the land–sea dual features, natural and anthropogenic attributes, and spatial heterogeneity of the island ecosystem was established, and the southern islands of Miaodao Archipelago in North China were taken as the study area. The IEV, its spatial heterogeneity, and its sensitivities to the evaluation elements were analyzed. Results indicated that the IEV was in status of mild vulnerability in the archipelago scale, and population pressure, ecosystem productivity, environmental quality, landscape pattern, and economic development were the sensitive elements. The IEV showed significant spatial heterogeneities both in land and surrounding waters sub-ecosystems. Construction scale control, optimization of development allocation, improvement of exploitation methods, and reasonable ecological construction are important measures to control the IEV.
Mostrar más [+] Menos [-]Potential health risk assessment of heavy metals via consumption of caviar of Persian sturgeon
2017
Sobhanardakani, S.
Caviar may contain high levels of toxic metals. Therefore determination of health risk assessment of the heavy metals in this luxury product is vital. In this study, an Inductively Coupled Plasma-Optical Emission Spectrometer and a Direct Mercury Analyzer were used to assess the contents of elements in caviar of wild Persian sturgeon. The results showed that the contents of Ba, Cr, Fe, Hg, Mn and Zn (mgkg−1) in caviar samples were 0.95, 0.27, 71.3, 1.44, 0.01 and 17.0, respectively. Also, Health Risk Index values were within the safe limits (HRI<1), and there is no potential health risk for adults and children via consumption of caviar. Finally, considering the contents of Fe and Hg were higher than Maximum Permissible Limits in the caviar samples related to the discharge of pollutants into the aquatic environment, monitoring of chemicals accumulation in the foodstuff is recommended.
Mostrar más [+] Menos [-]Potentially toxic filamentous fungi associated to the economically important Nodipecten nodosus (Linnaeus, 1758) scallop farmed in southeastern Rio de Janeiro, Brazil
2017
Numerous countries have been confronted with infectious diseases in mariculture activities, including fungi infections, although reports in scallops are scarce. Thus, this study aimed to investigate the occurrence of filamentous fungi in Nodipecten nodosus specimens from three marine farms in Southeastern Brazil. Eight fungi genera were observed in the branchial arches, intestine and muscle tissue of the scallop specimens. These include potentially toxin-producing species, such as Aspergillus, Penicillium and Fusarium. Their presence may lead to potential public health concerns, since all sampling sites showed the presence of fungi in all scallop organs, with special concern regarding edible muscle tissue. A significant number of species was observed at one of the study areas, which could indicate a previously unknown source of contamination, since increases in fungi species richness in polluted coastal waters have been reported. This is also, to the best of our knowledge, the first report of Pestalotiopsis in shellfish.
Mostrar más [+] Menos [-]Acoustic monitoring to document the spatial distribution and hotspots of blast fishing in Tanzania
2017
Braulik, Gill | Wittich, Anja | Macaulay, Jamie | Kasuga, Magreth | Gordon, Jonathan | Davenport, Tim R.B. | Gillespie, Douglas
Destructive fishing using explosives occurs in a number of countries worldwide, negatively impacting coral reefs and fisheries on which millions of people rely. Documenting, quantifying and combating the problem has proved problematic. In March–April 2015 231h of acoustic data were collected over 2692km of systematically laid transects along the entire coast of Tanzania. A total of 318 blasts were confirmed using a combination of manual and supervised semi-autonomous detection. Blasts were detected along the entire coastline, but almost 62% were within 80km of Dar es Salaam, where blast frequency reached almost 10blasts/h. This study is one of the first to use acoustic monitoring to provide a spatial assessment of the intensity of blast fishing. This can be a useful tool that can provide reliable data to define hotspots where the activity is concentrated and determine where enforcement should be focused for maximum impact.
Mostrar más [+] Menos [-]Spermatozoa: A relevant biological target for genotoxicity assessment of contaminants in the estuarine bivalve Scrobicularia plana
2017
Châtel, Amélie | Bruneau, Mélanie | Lièvre, Clémence | Goupil, Astrid | Mouneyrac, Catherine
Evaluation of DNA quality of gametes is a relevant method to predict potential consequences of pollutants in the next generations, as it allows to define adverse outcome pathways implicated in pollutant-mediated toxicity for risk assessment. In the present study, a comet assay was developed for the spermatozoa of Scrobicularia plana exposed to 10 and 100μg/L of benzo[a]pyrene (B[a]P) for 24h and 5days. The induction of apoptosis and repair mechanisms was assessed by determining caspase-3 activity and polymerase cell nuclear antigen (PCNA) mRNA expression level. Results showed that B[a]P induced high levels of DNA breaks that were associated with apoptosis for all the conditions tested, indicating that the spermatozoa were sensitive to B[a]P. PCNA gene expression was induced in animals exposed to the highest concentrations of B[a]P, suggesting that defence mechanisms were enhanced in these animals. This preliminary study demonstrated the utility of spermatozoa as a relevant biological target for genotoxicity assessment of contaminants and will enable to predict the effect of contaminants on future generations.
Mostrar más [+] Menos [-]Extremely high sulfate reduction, sediment oxygen demand and benthic nutrient flux associated with a large-scale artificial dyke and its implication to benthic-pelagic coupling in the Yeongsan River estuary, Yellow Sea
2017
Kim, Sŭng-han | Lee, Jae-seong | Hyun, Jung-Ho
We investigated environmental impact of large-scale dyke on the sediment geochemistry, sulfate reduction rates (SRRs), sediment oxygen demand (SOD) and potential contribution of benthic nutrient flux (BNF) to primary production in the Yeongsan River estuary, Yellow Sea. The sediment near the dyke (YE1) with high organic carbon (Corg) content (>4%, dry wt.) was characterized by extremely high SOD (327mmolm−2d−1) and SRRs (91–140mmolm−2d−1). The sulfate reduction accounted for 73% of Corg oxidation, and was responsible for strikingly high concentrations of NH4+ (7.7mM), PO43− (67μM) and HS− (487μM) in pore water. The BNF at YE1 accounted for approximately 200% of N and P required for primary production in the water column. The results present one of the most extreme cases that the construction of an artificial dyke may have profound impacts on the biogeochemical and ecological processes in coastal ecosystems.
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